The Love/Hate regulars will join other well-known actors and performers for Dublin Youth Theatre's 24 Hour Plays.
And it could be a bad case of first night nerves for former Boyzone star Keith Duffy, who will be making his debut on the Abbey stage.
Aidan Turner's girlfriend and star of Alice In Funderland, Sarah Greene, will also star in the 24 Hour fundraiser.
Dandelions writer Fiona Looney will be penning a play for the evening, while special musical guest Lisa Hannigan will perform three songs. Pauline McLynn will be doing a comic turn.
The 24 Hour Plays will see the group of 24 actors, six playwrights and six directors devise, write, rehearse and stage a series of six new short plays.
"They will all meet at 8pm in the evening on Saturday night," writer and organiser Philip McMahon explained.
"They all introduce themselves. Then the actors and directors go home and it's lockdown for the writers."
"They have to cast their plays, barter for actors and write a play all before 6am the following morning. It's a real panic station," he says.
"Every one is back in at 8am on Sunday morning and it's rehearsals till the show goes up at 7:30pm that night."
"The lucky ones are in the second half, which gives them a little more time to get off book," he laughs. The 24 Hour Plays are part of a fundraising event for Dublin Youth Theatre.
DYT have been producing theatre for 32 years and is one of Ireland's oldest youth theatre groups. Philip is artistic director.
"So many talented people have come out of DYT -- Aidan Gillen, Camille O'Sullivan, Brendan Courtney and Enda Walsh," he says. "The funding was slashed this year, so it's important to support them."
The first incarnation of the 24 Hour Plays was staged last February at the Project Arts Centre but DYT had to relocate due to demand.
"The event outgrew itself straight away," Philip says. "It sold out almost immediately. So we relocated to the Abbey because there are more seats and more room.
"It's chaos, creative chaos," he says. "It will be hectic but great fun. Lots of spontaneity, strong coffee and not much sleep."
"We have great actors and by the end of the night we will have six great new Irish plays." The collaboration came about when McMahon met Philip Naude, one of the original founders of 24 Hour Plays, an American company that has been doing this for 13 years.
The 24 Hour Plays take place on January 13 at 7.30pm.